Iron Filing Field Detector, 2017 by Raymond Hall from RIT Photo on Vimeo.

Raymond Hall

Iron Filing Field Detector, 2017

Video

@physicsfun
Department of Physics, California State University
Fresno; Fresno, California, United States

This video reveals the invisible: it shows the magnetic field lines around a dipole bar magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link up and align like tiny compass needles to follow and reveal the magnetic field lines associated with the permanent magnet underneath. Viscous silicone oil temporarily keeps the iron particles suspended yet allows for rotation and repositioning under the influence of the magnetic field. This is used as a demonstration device for physics mapping of magnetic fields.